AAT1142IWP-1.8-T1 View Datasheet(PDF) - Advanced Analogic Technologies
Part Name
Description
MFG CO.
'AAT1142IWP-1.8-T1' PDF : 21 Pages View PDF
SwitchRegTM
Functional Block Diagram
FB
PRODUCT DATASHEET
AAT1142
800mA Voltage-Scaling Step-Down Converter
VIN PVIN
MODE/SYNC
Voltage
Reference
EN/SET
SDA
SCL
Err.
Amp.
Control
Logic
DH
Logic
DL
LX
PGND
AGND
Functional Description
The AAT1142 is a high performance, 800mA step-down
converter with an input voltage range from 2.7V to 5.5V.
The AAT1142 uses Dynamic Voltage Management, which
allows the system host to quickly set the output voltage
through the integrated I2C or S2Cwire interface. Through
this interface, the host can change the output voltage to
track processor idle and active states, greatly extending
battery life without degrading system performance. I2C
provides an industry-standard, dual-line interface, while
S2Cwire provides a single-line, high-speed serial inter-
face.
The 2.2MHz switching frequency allows the use of small
external components. Only three external components
are needed to program the output from 0.6V to 2.0V.
Typically, one 4.7μF capacitor, one 10μF capacitor, and
one 2.2μH inductor are required.
The integrated low-loss MOSFET switches provide up to
93% efficiency. PFM operation maintains high efficiency
under light load conditions (typically <50mA). Pulling the
MODE/SYNC pin high allows optional PWM Only low noise
mode. This maintains constant frequency and low output
ripple across all load conditions. Alternatively, the IC can
be synchronized to an external clock via the MODE/SYNC
input. External synchronization can be maintained
between 1MHz and 3MHz.
At low input voltages, the converter dynamically adjusts
the operating frequency prior to dropout to maintain the
required duty cycle and provide accurate output regula-
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1142.2009.08.1.1
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